1. Field of the Invention
This invention concerns a process for the production of polyfluoroolefins by the catalytic addition of polyfluoroallylic fluorides to fluoroethylenes. 1:1 and 1:2 Adducts such as F-pentene-2 and F-heptene-3 can be formed selectively and reduced further to dihydro- or trihydropolyfluoroalkanes, which are useful as HFC cleaning agents. Higher boiling products, e.g., boiling points above 100.degree. C. are useful as solvents and stable liquids, particularly after the double bond has been saturated by hydrogenation, fluorination, or chlorination.
2. Technical Review
Various catalysts for the addition of polyfluoroallylic fluorides to fluoroethylenes are known.
G. G. Belen'kii, E. P. Lur'e, and L. S. German, UDC 66.095.253:547.413, Institute of Heteroorganic Compounds, Academy of Sciences of the USSR, Moscow (1975) use SbF.sub.5 as a catalyst for carrying out the alkylation of the fluoro derivatives of ethylene using perfluoropropylene and 2-H-perfluoropropylene.
Chang-Ming Hu, Hui Liu and Ze-Qi Xu, Reactions of Perchlorofluoro Compounds VI. Rearrangement of Higher Perchlorofluoroolefins and Their Reactions with Nucleophiles and Electrophiles, teaches the alkali fluoride ion induced formation of a TFE/HFP adduct.
The present invention employs an aluminum halide to catalyze the addition of an allyl fluoride to fluoroethylene.